V2483 Cygni / V2483 Cyg (= NSV 25486)
Light curve of the variable star V2483 Cygni / V2483 Cyg, constructed from 277 images taken with the Open University COAST telescope between 2017 July 23 and 2024 January 17. The images were taken using a V filter.
As of the date of writing (8 February 2024) this star is classified as an EB type eclipsing binary with a period of 112.4 d (GCVS, AAVSO VSX). However, the following phase diagram with this period suggests that this period is incorrect.
A slightly 'better' phase diagram is generated using a period of 115.24 days, as shown below.
Another 'reasonable' fit is obtained with a period of 57.6 days (ie half of 115.24 days) as shown below, which is the 'best fit' period as suggested by PERANSO/Anova,
The light curve appears to be possibly more consistent with an RV Tauri variable than an EB type. However, whatever the type of variable this object is, the period of 112.4 days does not relate to these particular observations.
[The above section added 2024 February 8]
[The above section added 2024 February 8]
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Historic analysis
Light curve of the variable star V2483 Cygni / V2483 Cyg, constructed from 217 images taken with the Open University COAST telescope between 2017 July 23 and 2022 January 2. The images were taken using a V filter.
As of the date of writing (20 February 2022) this star is classified as an EB type eclipsing binary with a period of 112.4 d (GCVS, AAVSO VSX).
However, neither this period, nor the 'best fit' period to my observations of 115.42d as determined by Peranso (see phase diagram below), generated a convincing eclipsing binary phase diagram.
However, neither this period, nor the 'best fit' period to my observations of 115.42d as determined by Peranso (see phase diagram below), generated a convincing eclipsing binary phase diagram.
Assuming that the 'period' of 115.42 days is significant, the light curve was divided up into observations contained within 115 day cycles and colour coded, generating the following light curve.
The corresponding phase diagram, using the same colour coding, is below;
Selecting just the black and the red cycles alone, the following phase diagram is generated.
Here, adjusting the period to 110.38d, the following phase diagram is generated.
By themselves, these two cycles are suggestive of an eclipsing binary light curve. However, using this period to plot the equivalent phase diagram using all the observations results in the following.
This is not consistent with an eclipsing binary light curve.
In conclusion, from these observations alone, the light curves and phase diagrams would appear to suggest that V2483 Cyg is an RV Tau type variable rather than an eclipsing binary.
These pulsating variables have light curves which can be mistaken for EB type eclipsing binaries, having alternate deep and shallow minima. See eg OGLE Atlas of Variable Star Light Curves.
APASS DR9 shows this star as having V=11.286 and B=12.627, hence B-V=1.341, say 1.34. As a single star, this would place it in spectral class K7, but this would vary according to phase, and the DR9 observations were only made on one night for each band. Given that reservation, this would be consistent with an RV Tau type. Spectroscopy of this variable would help to clarify just what type it is.
Also of note, whatever type of variable this is, the light curve shows a possibly periodic variation in the maximum magnitude. This has an apparent range of approximately half a magnitude and a time scale of very approximately 1000 days, but the 'gappy' data makes this conclusion unreliable.
I hope to obtain more (photometric) observations of this star in due course.
These pulsating variables have light curves which can be mistaken for EB type eclipsing binaries, having alternate deep and shallow minima. See eg OGLE Atlas of Variable Star Light Curves.
APASS DR9 shows this star as having V=11.286 and B=12.627, hence B-V=1.341, say 1.34. As a single star, this would place it in spectral class K7, but this would vary according to phase, and the DR9 observations were only made on one night for each band. Given that reservation, this would be consistent with an RV Tau type. Spectroscopy of this variable would help to clarify just what type it is.
Also of note, whatever type of variable this is, the light curve shows a possibly periodic variation in the maximum magnitude. This has an apparent range of approximately half a magnitude and a time scale of very approximately 1000 days, but the 'gappy' data makes this conclusion unreliable.
I hope to obtain more (photometric) observations of this star in due course.
[This page updated 2023 February 10]